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c#compilationprecompile

Are parameters of conditional methods (Debug.Assert(...)) optimized away in release mode?

I often have expensive linq queries embedded in Debug.Assert().

Ex: Debug.Assert(!orderShipmentStatusLogs.GroupBy(c => new { c.Id, c.StartDateTime }).Any(c => c.Count() > 1));

In this case orderShipmentStatusLogs can be a huge list - so this code may be slow.

For performance i'm asking myself whether that's smart or not, i know the Debug.Assert() method gets removed in release mode, but from reading the docs:

Any arguments passed to the method or attribute are still type-checked by the compiler. https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.conditionalattribute?view=net-6.0

I'm a bit doubtfull.

So am I safe here or am i accidently slowing my app down by adding in heavy assertions? Is the parameter to Debug.Assert() optimized away?

Solution

  • The entire Debug.Assert line is optimised away when you build in Release mode. So:

    Console.WriteLine("Before");
Debug.Assert(false);
Console.WriteLine("After");

    Becomes:

    Console.WriteLine("Before");
Console.WriteLine("After");

    You can see this using SharpLab. In Debug mode the Assert is still there but in Release it is gone.